| abstract |
A modified sol-gel method to create metal-rich siliceous material, such as colloidal silica or aluminosilicate particles is disclosed. Initially, the metal salt of choice is added to a silicic acid solution or a silicic acid solution containing aluminum salt. The aluminum is added to vary the metal-support interaction as it forms Al-O-Si linkages within the silica matrix. Besides aluminum, other metals can be added that form M-O-Si (M = Ti, B, etc.) linkages, which do not become reduced when treated with a reducing agent. Once the metal, silicic acid and/or aluminum salt is generated, it is subjected to colloidal growth by addition to a basic heel. Upon colloidal synthesis, the metal salt containing colloidal particle is left as is to maximize colloidal stability or is reduced with hydrazine to produce the zero valence metal-containing colloidal particle. Keeping a particle colloidal before use may be an effective method of forming a catalyst material as it can be easily spray-dried or mixed with other materials for extruded catalyst particles. |